Vintage Attwood Hot Water Heater Question.

[jbrowning]

I have a 1971 travel trailer that has an old Attwood hot water heater in it. Last season I noticed the water from the heat we coming out as a milkish color (this didn't happen with the cold water). I am wanting to clean out the inside of the hot water heater but where I drain it at is where the red knob is at. Did they make these old heaters with the knob or do you think someone put it on possibly when the lost the
drain plug?

I am wondering if I take the knob off, if I could find a drain plug that would fit in there so I can clean that tank out on a yearly basis.

Here are a few pictures of the front of the heater.

Water Heater

Water Heater

Water Heater

Water Heater

Thanks in advance for the help.
Jim

[CavemanCharlie]

I found where you hide your spare key.

[Old-Biscuit]

That red knob is the valve wheel for a 3/4" garden hose spigot.

Some previous owner replaced the OEM garden hose connection that American Appliance used on their RV water heaters.

You could replace it with a 3/4" CAP or 3/4" PLUG (depends on which part breaks loose----female hose bibb or male nipple in tank)

I would be VERY leery about trying to remove......no place to get a back up wrench on while trying to break loose hose bibb. May end up completely damaging drain hole threads OR thread bung cracking tank (part with threads welded to tank)

Unfortunate that the bibb wasn't turned sideways so garden hose could be connected and do a power flush thru Relief Valve.

You might have better luck putting a wrench on flats (bottom of hose bib next to tank) and then disassembly hose bibb (separate it just above hose connection)
Unscrew valve body remove valve stem/seal.
Clean out valve body....replace seal on end of stem, repack stuffing box (ACE Hardware will have parts)

[2oldman]

Water heaters are in houses. When they are in an RV they become hot water heaters.

[Chris_Bryant]

That red knob is the drain valve, and that is an old heater 🙂

I don't think that is n Atwood, fwiw. It looks more like a mobile temp, maybe, or an American Appliance.